In addition to considering Scout's growth throughout the novel, I think it's also important to consider the theme of maturity when it comes to Jem. Jem not only matures physically, like Scout noticing hair growing on parts of Jem's body, but his social and emotional maturity, as well. For example, Jem no longer wanting to hang out with his little sister and instead opting to hang out with another boy like Dill, his increasing moodiness and lessened tolerance for Scout, or his act of comforting Scout the night of the fire at Miss Maudie's house.
The theme of courage can also be a theme to consider. There are varying examples and degrees of courage being shown throughout the novel, from Jem going back to retreive his pants from the Radley yard to Mrs. Dubose beating her addiction to morphine before she dies.
The theme of prejudice, both racial and gender, is also very prevalent throughout the novel and should be considered. The racial prejudice the African-Americans of the community face on a daily basis is represented in the false accusations made against Tom Robinson. The gender prejudice that tom-boyish Scout constanstly faces from her Aunt Alexandra and sometimes Jem. Jem tells her several times she should act more like a "girl" and Aunt Alexandra is always getting on Scout's case to dress and act more like one, as well.
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Things for you to consider would be: Scout's growth through the novel, how her adult outlook is developed through the happenings within Maycomb at the time, significantly the idea of race. How she comes to understand the difference between good people versus bad people, and that it has nothing to do with colour or class. Ewells vs. Cunninghams vs. Robinsons vs. Finches vs. Radleys. Ask yourself who was right and who was wrong and WHY.